Photo by LBL Photographic Services
While learning more about the effect that John Gofman and Arthur Tamplin had on radiation protection regulations, I found an important story to share.
Excessive fear of low dose radiation among University of California Berkeley (UCB) researchers that were early pioneers in radiation and radioactive isotopes was directly influenced by a single dead rat. The researchers were told that the rat died from exposure to a relatively low dose of radiation from a short period near an unshielded cyclotron. John Gofman, a graduate student at UCB from 1939-1943 who worked with cyclotrons and isotopes under Glenn Seaborg, was one of the researchers who was taught that low doses of radiation could cause terrible consequences.
In reality, the rat had suffocated to death.
The senior scientists who knew the real cause of the rat’s demise — John Lawrence and Paul Aebersold — did not correct the myth for many years. They thought the fear from the dead rat story usefully encouraged young scientists to be more careful and self-protective around machines that could cause long term harm among careless users.
John Lawrence later expressed concern that the public had developed an excessive fear of low dose radiation. It isn’t clear if he recognized how he had contributed to the early stages of the contagious irrationality associated with low dose radiation.
History behind the story
The first hint of a new — to me — twist in the story of low dose fear development came while reading Our History: From Particle Physics to the Full Spectrum of Science. It is a 1989 piece that turned up in a “Gofman Tamplin radiation protection” search. About one third of the way through the document, I was startled by the following quote.
John Lawrence and the laboratory also pioneered in protecting people from radiation.
John Lawrence once recounted how early radiation safety criteria developed. “Paul Aebersold and I first put a rat in the cyclotron chamber about 1937. After the cyclotron had run,” said Lawrence, “I crawled back in there to see how the rat was doing. When I opened the canister, the rat was dead.
It scared all the physicists.
I later learned that the rat died of suffocation, not radiation, but I didn’t spread that news around. The physicists became much more interested in radiation protection after that.
Soon the cyclotron was heavily shielded. And the word got around about radiation hazards, because we reported some of our early findings in a paper presented at a meeting in Buenos Aires.”
(Paragraph breaks added.)
That whetted my appetite to find and learn more details about the suffocated rat that was used to encourage young researchers to adhere to radiation protection limits.
In 1979 and 1980, Sally Smith Hughes, a research historian at UCB’s Bancroft Library, interviewed John Lawrence — brother to the more well-known Ernest — about his life’s work. The transcript of the multi-discussion interview — along with some additional papers compiled into a document produced in 2000 — is available from the digital assets section of the UCB library. It includes an expanded version of the suffocated rat story.
Hughes: You and your brother were early warners of the dangers of neutrons. Was that warning heeded? Did other workers in the field take the necessary precautions?
Lawrence: I always felt badly about one thing. There were several places in the country that built cyclotrons in which people would get too close to the beam and look into it and then later have cataracts develop. We never had one here.
One of the first animals we exposed — I’m not sure that it wasn’t the first one — we encased in a little brass cylinder with an air inlet and an air outlet and this was placed within the cyclotron between the two poles of the magnet near the beryllium target which was being struck by deuterons (alpha particles). So Paul and I told Ernest to turn off the cyclotron because we wanted to go back and see how the rat was. Well, the rat was dead. That scared everybody because it had only been exposed for about a minute and the dose was very low. We were very scared and we then recommended increasing the shielding around the cyclotron. Later on we found that the rat died of suffocation but not of radiation.
There were maybe twenty people in the United States that got cataracts elsewhere. It was found that neutrons were very dangerous so nobody ever got close to this beam after this. It was a beautiful beam to see sort of like the rainbow. You see the beam coming out of the cyclotron and it s very tempting to get in and look at it. Then you’d get a big dose of neutrons, so we avoided that thereafter.
John Lawrence, pioneer researcher in radiation benefits
The Hughes-Lawrence interview transcript is a fascinating document. In 1979, Lawrence was a well-known, influential and experienced scientist near the end of a lengthy career. Lawrence was born in 1903, so he was in his late 70s and held the title of emeritus professor while Hughes interviewed him. He died in 1991.
The document describes how John Lawrence, who was a trained medical researcher, became interested in the beneficial use of radioactive isotopes being produced using his brother’s cyclotron inventions. His first experiment involved injecting mice that had leukemia with soluble radioactive phosphorous.
Within a few weeks, the mice exhibited significant improvement. In 1936, he was the first to use a similar treatment on a human when he successfully used radiophosphorous to help a young woman who had leukemia. “Soon the method became a standard treatment for the blood disease known as polycythemia vera, an uncontrolled proliferation of red blood cells.”
(Source: page 105 of the obituary included in the history document titled John H. Lawrence: Nuclear Medicine Pioneer and Director oF Donner Laboratory, University of California, Berkeley.)
Lawrence also used x-rays and other isotopes to treat patients during the remainder of the 1930s. He and his colleagues achieved notable successes. The activity level and investments in the labs took a prompt jump in 1942 when the Manhattan Project began. Oppenheimer asked him to set up a radiation protection program at Los Alamos, but Lawrence sent a young post doc named Louis Hempelmann instead. He explained that he had no interest in spending his career in radiation protection. He was much more interested in exploring isotope treatments.
Being a different type of person, interested in the positive applications of the products of atomic energy, I needed to stay here as a general medical influence in this whole program in connection with the very important war work of Ernest and the other people.
(Emphasis added. pg. 69)
Lawrence thought atomic energy was worth some risk
Pages 24-26 of Hughes’s interview include exchanges that indicate that Lawrence disagreed with the opposition to nuclear reactors. He thought people were being irrational by worrying about doses of radiation orders of magnitude below those that had demonstrated any evidence of harming people. He talked about the doses involved in various medical treatments and indicated thresholds that had been detected in several long-term follow-up studies. He then compared that knowledge to the fear of doses that were up to 1000 times lower. Here is an example quote.
Now several people, including people in this Laboratory, have written papers where they’ve followed patients who have received iodine-131 for Grave’s disease, thousands of cases. One of them is an Englishman by the name of Sir Eric Pochen. Fellow about my age; he’s still active. I saw him a couple of years ago in Europe.
They’ve shown that in a control group of people that have gotten this treatment of radioactive iodine for Grave’s disease, that there’s no increase in cancer or leukemia in them compared to the controls. Matter of fact, the controls have a little bit more. Now that’s a big dose of radiation. So you see, no one worries about that. Here you get people who get 6,000 millirads or 10,000 millirads. And here people get 2 or 3 millirads from reactors and they start worrying about it.
He blamed newspapers for not helping the public understand how the benefits of atomic energy overwhelm the risks.
One thing that’s not considered now in the newspapers is benefit versus risks. You have to take risks sometimes.
I think that’s one reason that some people are so much against the atomic reactor; they don’t realize the benefits from an atomic reactor in the form of electricity. All they think about is the risks.
Unfortunately, Lawrence apparently failed to recognize that what the public really needed to hear was an explanation from people like him that described how the evidence they had accumulated over many decades showed there was no risk from such low doses.
He could have made a big impact on both his colleagues and the public if he — an esteemed medical physics professor and a pioneer in the field — would have actively promoted a message like the following.
If radiation doses like those produced by reactors cause any damage at all, it is so low that it isn’t detectable. We’ve tried hard to detect it with very sensitive instruments and long periods of observation. There is no risk worth worrying about in a world full of hazards that caused immediate harm.
I apologize for my role in scaring people like John Gofman about the risks of radiation. Those young and normally fearless researchers worked in close proximity to machines that produced radiation doses that really could cause injuries. I wanted them to be especially careful, so I encouraged them think radiation was more deadly than it really is.
(Note: The words above are mine, not Lawrence’s. They are words I wish had been uttered, not words that have actually been uttered.)
